Abstract: In the search for effective radioprotectants, indazole analogues of 5-methoxytryptamine and 5-hydroxytryptamine and related derivatives were synthesized. The key intermediate 5-methoxyindazole-3-acetamide was prepared by the reaction of the corresponding ethyl ester with concentrated ammonium hydroxide solution in ethanol at room temperature. The resulted amide was dehydrated to nitrile with phosphorus oxychloride in pyridine. Reduction of the nitrile with lithium aluminium tetrahydride and anhydrous aluminium trichloride afforded the required amine. β-3-(5-Benzyoxyindazolyl)-ethylamine was obtained by the same procedure mentioned above and the total yield of this product increased from 10% as reported in literature based on the ester to 47%. This method was also used in the synthesis of other related derivatives. Among the tested compounds, 5-methoxyindazolylethylamine and 5-hydroxyindazolylethylamine showed good radioprotective activity.